This invention relates generally to a ballast for a triac dimmable fluorescent lamp, and more particularly to the dimming interface of a triac dimmable fluorescent lamp.
A triac dimmable compact fluorescent lamp includes a triac dimmer and a compact fluorescent lamp. The triac dimmer controls the amount of power supplied to and thereby the level of illumination provided by the compact fluorescent lamp. Triac dimmers are characterized by a cut-in angle, that is, a firing angle for turning on the triac. A minimum cut-in angle corresponds to maximum lamp light output. There is, however, no one minimum cut-in angle for turning on all triac dimmers. Effective interface with a compact fluorescent lamp is therefore difficult because of the variation in the minimum cut-in angle among different triac dimmers.
Accordingly, it is desirable to provide an improved compact fluorescent lamp which can effectively interface with triac dimmers having different minimum cut-in angles. The interface should translate the different minimum cut-in angles as representing a maximum lamp light output.